Scott Watson, of course, was the owner of the infamous sloop Blade, anchored near Furneax lodge in the Marlborough Sounds that fateful New Year’s eve in 1997. Two years later, he was convicted of luring fellow party-goers Ben Smart and Olivia Hope to his boat and murdering them. The following year, the Court of Appeal turned down his appeal.

The book is a meticulous dissection of the evidence against Watson, and fleshes out the allegations in Hunter’s 2003 documentary Murder on the Blade?

Let’s look at his case:

The main witness against Watson, Guy Wallace – the water taxi driver who supposedly dropped Watson (along with Smart and Hope) off on the Blade – now insists it wasn’t him – and that he was hoodwinked into making the identification.

Wallace, and everyone else who identified the guilty man, said he had at least medium-length, unkempt, wavy hair that evening. Photographs taken that day show that Watson’s hair was very short and trim.

Wallace and the other passengers at the time also insist that it wasn’t the Blade they were dropped off onto. It was a much bigger boat, with complex rigging; a ketch that you had to reach up to from a water taxi, unlike the Blade. What’s more, there were plenty of sightings of such a ketch in Endeavour Inlet and the Sounds that New Year.

The evidence of Watson’s arrival time at EerieBay kept getting pushed back during the investigation – to give Watson time to steam out into Cook Strait and dump the bodies, it seems. But even with his arrival at its latest, and his boatspeed at its maximum, the trip was physically impossible in that timeframe.

The Crown’s “two-trip” theory (sprung on the jury at the last moment) was that Watson had returned to the Blade at 2 am and then gone back to shore where he was seen at about about 2:45 am. But this is disproved by the occupants of the boat Blade was tethered to. Put together, their evidence is that he arrived sometime around 3 am, and certainly not significantly earlier.

Ah, yes, you think, as you read this. So why did he scrub the boat clean – including all those cassette tapes? In fact, the police’s own expert said only 30 percent of the surfaces were wiped, and probably fewer than half the cassettes.

But didn’t Watson paint the boat cabin afterward? Yes, as he had announced he was going to do the previous month.

But what about those scratches on the hatch – made by desperately scrabbling fingernails? Well, the hatch actually opened from the inside. Anyway, some of the scratches went right under the edge of the cover, and included parts on the side that couldn’t be reached when it was closed.

Still, weren’t there secret witnesses who said he’d confessed to them in jail? Well, yes, though their stories were implausible, and one has since recanted. The other got very friendly prosecution treatment after giving his evidence.

Okay – then how does Hunter explain Olivia’s hairs on Watson’s blanket? This is the single most damning piece of evidence. The thing to note here is that the scientist who looked at the bags of hairs from Watson’s blanket didn’t notice any blonde hairs, and couldn’t find any hairs at all that were testable for DNA. It was only after the police had visited Olivia’s home and taken samples of her hair when the scientist took another look at the bags of hairs from the blanket – and found a hair that matched Olivia’s. I think we can be forgiven a doubt about that evidence.

Hunter asserts that those involved in securing Watson’s conviction were party to a horrendous miscarriage of justice. He says the police were deceptive and tunnel-visioned, the media helped spread damaging misinformation, and the prosecutors misled the jury. They’re serious allegations. But Hunter explains his grounds for them. His case is persuasive. The onus now, I think, is on the police and prosecution to answer it. What has Hunter got wrong? What other evidence has he missed out that should convince us that Watson is guilty? Is there a good response to his allegations of police and prosecution misconduct?

I phoned the police and asked those questions. I was told that Rob Pope, who was in charge of the Watson investigation and is now Deputy Police Commissioner, hadn’t read the book, and didn’t want to relitigate the case, which after all had been through an appeals process.

Not good enough, I say. Hunter has raised serious questions here, and they go to the heart of public confidence in the administration of justice. The fact that an innocent man may be in jail is just the beginning of what should trouble us about this case.